1. Field of the Invention
The present invention relates to an actuator arm of a hard disk drive.
2. Background Information
Hard disk drives contain a plurality of magnetic heads that are coupled to rotating disks. The heads write and read information by magnetizing and sensing the magnetic fields of the disk surfaces. Each head is attached to a flexure arm to create a subassembly commonly referred to as a head gimbal assembly (“HGA”). The HGA's are attached to an actuator arm which has a voice coil motor that can move the heads across the surfaces of the disks.
FIG. 1 shows a typical actuator arm 1 of the prior art. The actuator arm 1 includes a plurality of beams 2 that extend from a bearing section 3. The bearing section and beams are constructed from a homogenous piece of aluminum. A plastic insert 4 is attached to the bearing section 3 and a voice coil 5 is attached to the insert 4.
Information is stored in radial tracks that extend across the surfaces of each disk. Each track is typically divided up into a number of segments or sectors. The voice coil motor and actuator arm can move the heads to different tracks of the disks.
The disks of the drive are rotated by a spindle motor. The rotating disks create a flow of air within the disk drive. The heads each have surface features that form air bearings between the heads and the disks. The air bearings reduce/eliminate mechanical wear between the heads and the disk surfaces.
The air flow may also cause vibration in the actuator arm. The vibration may cause oscillating movement of the heads and track mis-registration that degrades the performance of the disk drive. Additionally, the heads may also have undesirable oscillating movement due to external shock or vibration loads. It would be desirable to provide an actuator arm that damps shock and vibration loads. It would be desirable to provide a damping actuator arm that was relatively easy and inexpensive to implement in a hard disk drive.